Integrated management of glyphosate-resistant horseweed (Erigeron canadensis) with tillage and herbicides in soybean

2019 ◽  
Vol 33 (6) ◽  
pp. 859-866 ◽  
Author(s):  
Parminder S. Chahal ◽  
Amit J. Jhala
Keyword(s):  
Integrated Management ◽  
Block Design ◽  
Integrated Approach ◽  
Field Studies ◽  
The United States ◽  
Soybean Yield ◽  
Growing Seasons ◽  
Two Factors ◽  
Sites Of Action

AbstractGlyphosate-resistant (GR) horseweed is one of the most common and troublesome weeds in soybean production fields in several states in the United States, including Nebraska. The evolution of horseweed resistant to several herbicide sites of action has prioritized an integrated approach, including tillage, for effective management of this problem weed. The objectives of this study were to evaluate the effect of tillage or herbicide applied in fall or spring followed by a PRE, POST, and PRE followed by a POST herbicide program for GR horseweed control as well as GR soybean injury and yield in Nebraska. Field studies were established in the fall 2014–2015 and 2015–2016 growing seasons using a factorial randomized complete block design with shallow tillage or herbicide applied at different timings as two factors. Shallow tillage was accomplished using a 50-cm-wide rototiller operated at a depth of 10 cm. At soybean harvest, tillage applied the previous year in fall or spring without any follow-up herbicide treatment provided 79% to 88% horseweed control compared with 27% and 56% control with 2,4-D plus carfentrazone applied in fall and spring, respectively. Tillage or herbicide applied in fall or spring followed by a PRE, POST, or PRE and POST herbicide provided 82% to 99% GR horseweed control at soybean harvest. Soybean yield in this study was similar in most treatments. Tillage or herbicide applied in fall or spring provided similar horseweed control and soybean yield when followed by a PRE, POST, or PRE and POST herbicide; therefore, fall- or spring-applied herbicides can be rotated with shallow tillage for integrated season-long horseweed management.

Factors Predicating Loss to Follow-Up With Rescreening in Early Hearing Detection and Intervention Programs

2019 ◽  
Vol 100 (2) ◽  
pp. 213-223 ◽  
Author(s):  
Wendy Zeitlin ◽  
Charles Auerbach ◽  
Susan Mason ◽  
Lynn Spivak ◽  
Andrew Erdman
Keyword(s):  
Hearing Loss ◽  
Maternal Depression ◽  
Hospital Discharge ◽  
The United States ◽  
Prospective Longitudinal Study ◽  
Loss To Follow Up ◽  
Two Factors ◽  
Prospective Longitudinal ◽  
The Impact

Most infants born in the United States are screened for hearing loss prior to hospital discharge in Early Hearing Detection and Intervention (EHDI) programs; however, many infants who do not pass their screening do not return for recommended rescreening and are considered lost to follow-up (LTF). This research addresses this by examining factors related to LTF at the point of rescreening. A prospective longitudinal study tracked 166 families whose newborns were referred for additional testing upon hospital discharge. Analysis identified two factors related to being LTF: parents’ perceptions of hearing loss as having the potential to impact their child’s future and maternal depression; however, social support moderated the impact of maternal depression. Specific implications for working with families is discussed.

scholarly journals Off-Target Movement of Diglycolamine Dicamba to Non-dicamba Soybean Using Practices to Minimize Primary Drift

2019 ◽  
Vol 33 (1) ◽  
pp. 24-40 ◽  
Author(s):  
Gordon T. Jones ◽  
Jason K. Norsworthy ◽  
Tom Barber
Keyword(s):  
New Technology ◽  
Field Studies ◽  
The United States ◽  
Yield Reduction ◽  
Growth Stages ◽  
Target Movement ◽  
Soybean Yield ◽  
Wind Speeds ◽  
Height Reduction ◽  
Over The Top

AbstractSoybean with resistance to dicamba (DR soybean) and glyphosate and cotton with resistance to glyphosate, glufosinate, and dicamba were recently commercialized in the United States and have been readily adopted. To evaluate results of over-the-top application of dicamba in DR crops, field studies were designed to examine off-target movement using proposed sprayer setup recommendations. Association analysis and nonlinear regression techniques were used to examine the effects of 26 field-scale drift trials conducted in 2014 and 2015 during soybean reproductive development (R1 through R6). The greatest predictors (injury, height reduction) of soybean yield reduction generally occurred and had steeper relationships after drift events at the R1 growth stage than at later stages. Using non-DR soybean as an indicator, dicamba was documented to move as much as 152 m from the application area (distance to 5% injury). Instances of height reduction (5%) differed among growth stages, with the greatest distance occurring at R1 (83.4 m). Soybean yield reduction was erratic, with the greatest distance to 5% loss in yield occurring at 42.8 m after an R1 drift event. Overall, the data suggest flowering-stage soybean is more sensitive than later reproductive soybean to injury, height reductions, and yield loss. Average and maximum wind speeds did not account for the injury documented from dicamba, and it is hypothesized that other meteorological variables also play a notable role in dicamba off-target movement as well as growing conditions following exposure. With concerns surrounding off-target movement of dicamba, proper stewardship of this new technology will be key to its longevity.

Effect of Weed Management Strategy and Row Width on Nitrous Oxide Emissions in Soybean

Weed Science ◽  
2015 ◽  
Vol 63 (4) ◽  
pp. 962-971 ◽  
Author(s):  
Rebecca R. Bailey ◽  
Thomas R. Butts ◽  
Joseph G. Lauer ◽  
Carrie A. M. Laboski ◽  
Christopher J. Kucharik ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Soil Moisture ◽  
Greenhouse Gas ◽  
Weed Management ◽  
Management Strategy ◽  
Block Design ◽  
The United States ◽  
Nitrous Oxide Emissions ◽  
Soybean Yield ◽  
Row Width

Nitrous oxide (N2O) is a potent greenhouse gas with implication for climate change. Agriculture accounts for 10% of all greenhouse gas emissions in the United States, but 75% of the country's N2O emissions. In the absence of PRE herbicides, weeds compete with soybean for available soil moisture and inorganic N, and may reduce N2O emissions relative to a weed-free environment. However, after weeds are killed with a POST herbicide, the dead weed residues may stimulate N2O emissions by increasing soil moisture and supplying carbon and nitrogen to microbial denitrifiers. Wider soybean rows often have more weed biomass, and as a result, row width may further impact how weeds influence N2O emissions. To determine this relationship, field studies were conducted in 2013 and 2014 in Arlington, WI. A two-by-two factorial treatment structure of weed management (PRE + POST vs. POST-only) and row width (38 or 76 cm) was arranged in a randomized complete block design with four replications. N2O fluxes were measured from static gas sampling chambers at least weekly starting 2 wk after planting until mid-September, and were compared for the periods before and after weed termination using a repeated measures analysis. N2O fluxes were not influenced by theweedbywidthinteraction orwidthbefore termination, after termination, or for the full duration of the study at P ≤ 0.05. Interestingly, we observed that POST-only treatments had lower fluxes on the sampling day immediately prior to POST application (P = 0.0002), but this was the only incidence whereweedinfluenced N2O fluxes, and overall, average fluxes from PRE + POST and POST-only treatments were not different for any period of the study. Soybean yield was not influenced bywidth(P = 0.6018) orweedbywidth(P = 0.5825), but yield was 650 kg ha−1higher in the PRE + POST than POST-only treatments (P = 0.0007). These results indicate that herbicide management strategy does not influence N2O emissions from soybean, and the use of a PRE herbicide prevents soybean yield loss.

scholarly journals Overwintering of Wheat Stripe Rust Under Field Conditions in the Northwestern Regions of China

Plant Disease ◽  
2019 ◽  
Vol 103 (4) ◽  
pp. 638-644 ◽  
Author(s):  
Xiangming Xu ◽  
Lijie Ma ◽  
Xiaoping Hu
Keyword(s):  
Stripe Rust ◽  
Puccinia Striiformis ◽  
Integrated Management ◽  
Management Strategies ◽  
Disease Onset ◽  
Field Studies ◽  
Winter Hardiness ◽  
Field Conditions ◽  
Winter Survival ◽  
Growing Seasons

Stripe rust, caused by Puccinia striiformis f. sp. tritici Erikss., is an important disease of wheat worldwide. Identification of pathogen survival hot spots is important for predicting disease onset and subsequent spread to other regions, and such understanding is essential for developing integrated management strategies. We conducted field studies to determine the relationship of P. striiformis f. sp. tritici overwintering potential to winter temperatures in 10 sites in the northwest of China in three growing seasons (2011–12, 2012–13, and 2013–14). The fungus survived better in wheat cultivars with stronger winter hardiness than in those with weaker winter hardiness. Windowpane analysis suggested that P. striiformis f. sp. tritici winter survival is related to temperatures in the coldest period from mid-December to late January. β Regression showed that P. striiformis f. sp. tritici winter survival was negatively related to the number of days with daily average temperature <−2°C for cultivars with weak winter hardiness and <−4°C for cultivars with both moderate and strong winter hardiness. Models developed under constant temperature experiments greatly underestimate the P. striiformis f. sp. tritici overwinter potential under field conditions. This underestimation probably results from the possibility that P. striiformis f. sp. tritici in wheat tissues may have increased tolerance to low temperatures because of acclimation to gradual temperature changes under field conditions. The present models can be used to predict quantitative risks of P. striiformis f. sp. tritici overwintering in winter-wheat-growing regions for timely implementation of regional disease management strategies.

scholarly journals Adding manure and zeolite to improve soil chemical properties and increase soybean yield

2020 ◽  
Vol 17 (1) ◽  
pp. 1
Author(s):  
Slamet Minardi ◽  
Isna Luthfa Haniati ◽  
Alif Husna Lantip Nastiti
Keyword(s):  
Block Design ◽  
Chemical Properties ◽  
Soil Chemical Properties ◽  
Cow Manure ◽  
Cultivated Land ◽  
Soybean Yield ◽  
Randomized Block Design ◽  
Two Factors ◽  
Potential Area ◽  
Poor Soil

Increasing domestic soybean production is an important part of the effort to reduce reliance on imports. One potential area for improvement is developing soybean crops in Alfisols. Alfisols require intensive effort due to their poor soil chemical properties. Manure and zeolite were proposed as candidate materials that could be used to improve soil chemical properties to support plant growth and increase the productivity of cultivated land. The experiment was designed to study the addition of manure and zeolite on soil chemical properties of Alfisols and soybean yield. The experimental design was arranged in a factorial completely randomized block design with two factors—three rates of zeolite (Z0 = 0 t ha<sup>-1</sup>, Z1 = 2.5 t ha<sup>-1</sup> and Z2 = 5 t ha<sup>-1</sup>) and three manure variables (P0 = no manure, P1 = 5 t ha<sup>-1</sup> cow manure, and P2 = 5 t ha<sup>-1</sup>  quail manure)—with three replications. The results showed that a combination of 5 t ha<sup>-1</sup> zeolite and cow manure increased soybean yield. However, zeolite 5 t ha<sup>-1</sup> resulted in the greatest improvement in soil chemical properties—the highest CEC, soil organic matter percentage, and pH.

Effects of solarization on critical period of weed control in sesame (Sesamum indicum L.)

2017 ◽  
Vol 46 (4) ◽  
pp. 272-278 ◽  
Author(s):  
Mehdi Madandoust ◽  
Ahmad Ranjbar
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Block Design ◽  
Dry Weight ◽  
Field Studies ◽  
Convolvulus Arvensis ◽  
Leaf Initiation ◽  
True Leaf ◽  
Growing Seasons ◽  
Bud Emergence

In order to determine the critical period of weed control in sesame, field studies were conducted during the 2014 and 2015 growing seasons in Estahban, Iran. The experiments were conducted based on factorial arrangement which involved a randomized complete block design with three replications. The first factor was conducted in two weed-infested and weed-free series until different phonological stages of sesame growth. These stages included a third pair true leaf initiation, first bud emergence, 50% opened flowers, and minor plants stop flowering, and the second factor was related to solarization which was achieved using light and dark polyethylene plastics and control. The results showed that the critical period of weed control was influenced by solarization so that solarization using light polyethylene plastic could severely shorten the critical period. Weed dry weight also gradually reduced, with increase in weed control, and the formation of first flower buds decreased significantly. Solarization did not have a great effect on the number of Convolvulus arvensis L. among the weeds, but its effect on one-year-old weeds was evident. Thus, weed infestation until the third pair true leaf initiation did not reduce sesame yield.

scholarly journals Sesame (Sesamum indicum L.) Response to Delayed Applications of Preemergence Herbicides Applied 3 or 6 Day after Emergence

2021 ◽  
pp. 34-50
Author(s):  
W. James Grichar ◽  
Jack J. Rose ◽  
Peter A. Dotray ◽  
Joyce A. Tredaway ◽  
Muthukumar Bagavathiannan ◽  
...  
Keyword(s):  
Block Design ◽  
Field Studies ◽  
Application Timing ◽  
Plot Size ◽  
Growing Seasons ◽  
Leaf Chlorosis ◽  
Randomized Complete Block Design ◽  
Herbicide Treatments ◽  
Preemergence Herbicides ◽  
Significant Injury

Aims: Field studies were conducted to determine sesame response to the pre-emergence herbicides (acetochlor at 1.7 kg ai ha-1; S-metolachlor at 0.72, 1.43, and 2.86 kg ai ha-1; dimethenamid-P at 0.84 kg ai ha-1; pethoxamid at 0.22 kg ai ha-1; pyroxasulfone at 0.09 kg ai ha-1and bicyclopyrone at 0.12 and 0.24 kg ai ha-1) applied 3 or 6 days after 50% emergence. Study Design:  Randomized complete block design with 3-4 reps depending on location. Place and Duration of Study: Sesame growing areas of Alabama, Mississippi, and Texas during the 2016 through 2018 growing seasons. Methodology: Treatments consisted of a factorial arrangement of herbicide treatments at two early POST application timings. A non-treated control was included for comparison. Crop oil concentrate (Agridex®, Helena, Collierville, TN 38017) at 1.0% v/v was added to all herbicide treatments. Plot size was either five rows (76 cm apart) by 9.1 m or four rows (101 cm apart) by 7.3 m depending on location. Only the two middle rows were sprayed and the other rows were untreated and served as buffers. Sesame cultivars were seeded approximately 1.0 to 2.0 cm deep at 9 kg/ha at all locations. Injury was evaluated early-season, 7 to 27 days after herbicide application (DAA), and later, 28 to 147 DAA, based on a scale of 0 (no sesame injury) to 100 (complete sesame death). Injury consisted of stuntingand leaf chlorosis and/or necrosis. Results: All herbicides tested resulted in significant injury to sesame at some location and application timing. None of the herbicides evaluated are safe to use early POST on sesame without causing significant injury.  Conclusion: The ability of sesame to recover from significant injury and compensate for injury led to no yield loss in many instances. However, levels of injury observed are not acceptable by growers and will not allow the use of these herbicides soon after sesame emergence.

PENGARUH KOMPOS SAMPAH KOTA DAN PUPUK KANDANG SAPI TERHADAP PERTUMBUHAN DAN HASIL TANAMAN PAKCOY (BRASSICA RAPA, L. CHINENSIS) PADA ALUVIAL KABUPATEN INDRAMAYU

2018 ◽  
Vol 9 (2) ◽  
pp. 153-163
Author(s):  
Wiwik Ambarsari ◽  
Henly Yuliana
Keyword(s):  
Plant Height ◽  
Brassica Rapa ◽  
Block Design ◽  
Cattle Manure ◽  
Growth And Yield ◽  
Randomized Block Design ◽  
Two Factors ◽  
Number Of Leaves ◽  
Experimental Garden

The study aimed to determine the effect of the combination of city waste compost and cattle manure on the growth and yield of pakcoy plants (Brassica rapa, L. Chinensis) in Aluvial, Indramayu Regency. The study was conducted at the Experimental Garden of the Faculty of Agriculture, Wiralodra University, Indramayu Regency from March to August 2018. This study used Factorial Pattern Randomized Block Design with two factors. The first factor is city waste compost and the second factor is cattle manure with 4 levels: 0%, 3.0%, 6.0%, and 9.0%, repeated twice. The results showed that there was an independent influence between city waste compost and cattle manure on plant height and number of leaves. The best combination to increase the feasibility weight of pakcoy consumption is by giving city waste compost 9.0% (S4) and cattle manure 6.0% (K3).

Use of Biomonitoring to Control Toxics in the United States

1988 ◽  
Vol 20 (10) ◽  
pp. 101-108 ◽  
Author(s):  
Nelson A. Thomas
Keyword(s):  
Water Quality ◽  
Chronic Toxicity ◽  
National Policy ◽  
Single Species ◽  
Field Studies ◽  
The United States ◽  
Toxicity Tests ◽  
Toxic Pollutants ◽  
Receiving Waters ◽  
Biological Field

A biomonitoring program has been developed in support of the National Policy for the Development of Water Quality-Based Permit Limitations for Toxic Pollutants. The program focuses on the use of laboratory toxicity tests on aquatic plants and animals to predict ecosystem impact caused by toxic pollutants. Both acute and chronic toxicity tests were developed to test effluents and ambient waters. Laboratory and biological field studies were conducted at nine sites. Single species laboratory toxicity tests were found to be good predictors of impacts on the ecosystem when two or more species were used. Biomonitoring can be undertaken either on effluents and/or on the receiving waters. In that toxicity related to seeps, leachates and storm sewers has often been found upstream from dischargers, it is beneficial to conduct both effluent and ambient biomonitoring.

Questions

2018 ◽  
Author(s):  
James L. Gibson ◽  
Michael J. Nelson
Keyword(s):  
United States ◽  
African Americans ◽  
Supreme Court ◽  
Legal System ◽  
Public Support ◽  
The United States ◽  
Future Research ◽  
White Americans ◽  
Two Factors ◽  
The U.S

We have investigated the differences in support for the U.S. Supreme Court among black, Hispanic, and white Americans, catalogued the variation in African Americans’ group attachments and experiences with legal authorities, and examined how those latter two factors shape individuals’ support for the U.S. Supreme Court, that Court’s decisions, and for their local legal system. We take this opportunity to weave our findings together, taking stock of what we have learned from our analyses and what seem like fruitful paths for future research. In the process, we revisit Positivity Theory. We present a modified version of the theory that we hope will guide future inquiry on public support for courts, both in the United States and abroad.

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